I'd agree if you say he should be more clear, throughout and detailed with his reviews, but to say he's a liar for being aware of certain scientific findings but not actually using it as a cornerstone of his audio journey? I think that's a stretch.
As for his recommendation, his list (and to some extent, other reviewer's lists like Crinacle's) is based on his preferences and he mentioned it several times. "He thinks its the best headphones he listened to" sounds pretty reasonable to me, he didn't go out of his way to say it's undoubtedly the greatest headphones ever like it's something set in stone. You can shit on his taste for liking badly designed, overpriced distortion factory and stuff, maybe call him ignorant if you deem so. Additionally, the last time I check, his stance on cables were pretty much alike to what's suggested here as well.
And hey, science does not reflect absolute satisfaction in this hobby, does it? It provides what's objectively the truth, but it does not mean everyone will like it (as in enjoy it), or have the ability to bend their taste to it.
For example you can check the Zero IEMs thread, it passed all objective metrics with flying colors, it's a record-breaker IEMs and yet not everyone who bought it there was happy with it (granted, it is only a minority). Is it their hearing's fault for not being able to like it? Or is it the reviewer's fault for giving it such praises? I don't think either is correct. His listening preference not matching with the scientific findings is not a causal evidence that he's a liar.